Ignition system



J. H. HUNT. IGNITION SYSTEM. APPLICATION FILED MAR. 24,19I9.

Patented Feb; 14,1922.

2 SHEETS-SHEET l- J.H.HUNT..

IGNITION SYSTEM.

APPLICATION FILED MAR. 24. 19l9.

1,406, 1 90, Patented Feb. 14, 1922.

2 SHEETS-SHEET 2. 2773911277:

Esner'aTar UNITED STATES JOHN H. HUNT, OF DAYTON, OHIO, ASSIGNOR TO THE DAYTON ENGINEERING" LABORATORIES COMPANY, A CORPORATION OF OHIO.

IGNITION SYSTEM. 7

Specification of Letters Patent. Patented F b. 14,

Application filed March 24, 1919. Serial No. 284,806.

To all whom it may concern: I

Be it known that I, J OHN H. HUNT, a citizen of the United States of America, residing at Dayton, county of Montgomery,

State'of'Ohio, have invented certain new and secondary batteries.

Other and further objects and advantages of'the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

Referring to the drawings:

Fig. 1 is an ignition wiring diagram together with a diagrammatic end elevation of an engine, showing one embodiment of the invention; andv Fig. 2 is a fragmentary wiring diagram showing the changes necessary to be made in the ignition wiring diagram shown in Fig. l in order to adapt the ignition system for a single cylinder engine.

Fig. 3 is a side elevation view showing the magneto and generator and connecting gear- Referring to the drawings, 20 indicates an internal-combustion engine having a crank shaft 21 carrying a gear 22. Gear 22 cooperates with gear 23 to drive a cam shaft 24, which carries the cams operating the valve rods of the engine, one of which is shown at 25. I Shaft 24 carries a timer cam 26 cooperating with a breaker lever 27 pivot-' ally mounted upon a timer cup 28. Lever 27 carries a movable contact 29 normally held in yielding engagement with a stationary contact 30 by means of leaf spring 31 which presses against the timer cup 28 and the breaker lever 27.

Gear 23 cooperates with gear 33 to drive the armature 34 of a generator 35. Brushes 36 and'37 conduct the current generated to the main leads 38 and 39 with which lamps or other power translating devices 40 are connected. Excitation for the generator is provided by means of a shunt field winding 41 connected at one end with the brush 36 and at the other with a vibrating switch 42 which in turn is connected by wire 43 with the brush 37. The switch 42 normally short circuits a resistance winding 44 out of the shunt field circuit. A voltage coil- 45 controls the operation of the switch 42 so that when the voltage across the generator terminals exceeds a certain amount, the switch 42 will be opened, decreasing the field excitation. The windings 44 and 45 may be magnetically related so that current passing through the coil 44 will produce a magnetic field in opposition to that produced by current flowing through the coil 45. This relation is .indicated by arrows 44 and 45 The relation of the gearing 22, 23 and 33 is such that the generator will be driven at engine speed. Gear 33 is directly con nected with a gear which drives a pinion 5.1 at substantially four times engine speed. Gear 51 is mounted upon the shaft 52 of a low tension magneto generator. Shaft 5.2 carries timer cam 53 and an armature 54, the terminals of which are connected to slip rings 55 and 56. Brushes 57 and 58 cooperate with the slip rings 55 and 56 respectively, to conduct current to, the wires 59 and 60 respectively. Armature 54 cooperates with a permanent field magnet 61.

' Wire 59 is connected with a breaker lever 62 controlled by cam 53. Lever 62 carries a movable contact 63 cooperating with a stationary contact 64 which is connected .by

wire 65 with the wire 60. Condenser 66 is connected in parallel with the contacts 63 and 64. Spring 67 normally maintains contacts 63 and 64 in engagement under yielding pressure. v

Current for ignition purposes during the normal running operation of the engine is supplied from the generator 35. Generator terminal or lead 38 is connected by switch 7 O with ignition resistance 71 and ignition coil primary winding 72. Finding 72 is connected to contact 29 by wire 73, timer cup 28, spring 31 and lever 27. Contact .30 is connected by wire 74 with the generator lead 39. Condenser 32 is connected inparallel with the contacts 29 and 30. The secondary ignition circuit includes ignition coil secondary winding 75 which isgrounded on the. engine frame by wire 76 and is connected with a distributor 77. Distributor rotor 79 cooperates with contacts 79 to distribute impulses to the various spark plugs of the engine, one being shown at 78.

The magneto generator cooperates with this same ignition coil to produce ignition for starting the engine. Wire 59 is connected with the wire 73 by means of a manually operated switch 80, and the wire 60 is connected with wire 74 by means of an electric switch 81. Switch 81 comprises a winding 82 connected across the generator leads 38 and 39, which controls the movement of switch arm 83 normally held by spring 84 in engagement with contact 85. Under certain conditions arm 83 may be attracted away from contact 85 and into engagement with a contact 86 connected by a resistance 87 with the wire 59.

The operation of the invention is as follows:

The magneto switch 80 and the primary ignition switch 70 are closed to control the ignition circuits. The engine is started manually and the magneto armature 54E will be rotated at a rate which will cause impulses to be generated of suflicient magnitude for nition purposes. Each time the contacts 63 and 64 are opened by the cooperation of the cam 53 with the breaker lever the short circuit around the magneto armature 5% will be interrupted. Where the magneto and engine are geared four to one, a series of eight equally spaced current impulses will be generated for each revolution of the engine crank shaft 21. If the contacts 29 and 30 were maintained apart at all times all of these eight impulses would pass to the primary winding 72. Considering for the mo ment that contacts 29 and 30 have just opened and that the contact 63 has just moved away from contact 64, an impulse will pass from the magneto armature 54: to the coil winding 72 through the following circuit: slip ring 55, brush 57, wire 59, switch 80, wire 73, coil winding 72, resistance 71, switch 70, Wire 38, armature 3%, wire 39, wire 74, switch contact 85, arm 83, wire 60, brush 58 and slip ring 56 to magneto armature 54.

However, the contacts 29 and 30 are not separated at all times during the operation of the system but are closed during two intervals for each revolution of the crank shaft 21. The relation of the cams 24L and 53 is such that contacts 29 and 30 will remain closed during the time in which 'every other two of the impulses generated by the magneto are created. It will result therefore that every other of these magneto impulses will be short circuited by the contacts 29 and 30 away from the coil winding 72. Therefore at the time. in which the contacts 29 and cuited current impulse passing through the coil 72 at the time contacts 29 and 30 are closed, could be transformed into an effective sparking impulse, the timing of the distributor rotor 79 is such that it will not be in distributing position with any of the contacts 7 9 to distribute a sparking impulse to any of the engine cylinders. It is apparent therefore that a double protection against prematuring ignition has been provided: first by short circuiting the magneto impulses before they can be transformed into sparking impulses, and second, by arranging the distributor so that any premature sparking impulse would not be delivered to the engine cylinders.

After the engine has become self-operative, the generator 35 will supply sufficient current for ignition purposes. hen the generator is supplying current the primary ignition circuit will include wire 38 leading out from armature 3%, switch 70, resistance 71, coil 72, wire 73, contacts 29 and 30, wire 7 4. main lead 39 which is connected with the armature 3%. The contacts 29 and 30 are separated at the proper time in the engine cycle to cause a reduction in current in the coil 7 2 and the resulting discharge of a sparking impulse from the secondary coil 75 to the distributor 77 and to the spark plugs 7 8 through the medium of the distributor rotor 7 9 and the contacts 79*.

The magneto ignition circuit can be rendered ineffective by opening the switch 80 or automatically upon the reaching of a predetermined engine speed. At such a speed the voltage generated may be sufficient to cause the winding 82 to overcome the tension of the spring 8-1 and to draw the switch arm 85 away from contact 85 and into engagement with the contact 86. The magneto generator will then be rendered ineflectire to deliver current impulses to the ignition coil. and will discharge periodically through the resistance 87.

The relation of the operation of breakers 2G and 62 is such that the timing of the ignition provided by the magneto in combination with the ignition coil is later relative to the engine cycle, than the timing of the ignit-ion provided by the generator in combination with the ignition coil. This arrangement is desirable since it is advantagcous to start the engine with the ignition retardec. Thus it will be seen that I have provided means for automatically changing from a relatively retarded starting ignition to a relatively advanced ignition for the running operation of the engine.

While I have described my invention in connection with a multi-cylinder engine it is apparent that it can be used as well with a single-cylinder engine. The changes in the system which are necessary to change from multi-cylinder to single-cylinder ignition a are shown Fig. 2. The secondary ignition coil winding 7 5 is grounded at one end and connected directly at the other end with the spark plug of the engine. The only other change that is necessary is to provide the timer cam with one lobe as indicated by the cam 26 In this manner the contacts 29 and 30 will be opened only at the begin ning of theeXplosion stroke or slightly before as is the case of advanced ignition; The current impulses generated by the magneto generator will be short circuited away from the ignition coil by contacts 29 and 30, with the exception of those impulses which are generated at the explosion stroke. 7

From the foregoing description, it is apparent that an ignition system constructed in accordance with the present invention possesses several important advantages, namely: No primary or storage batteries are required, thus eliminating the expense of initial cost and maintenance. Such a system is well adapted for use with a power plant in'which no storage batteries are required but the engine is kept running as long as there is any demand for power. It is also advantageous to have the starting ignition retarded relatively tothe running ignition in order to facilitate starting, and to have the ignition timing advanced automatically when the engine becomes self-operative.

In the apparatus described, the generator is geared so as to run at engine speed and the magneto so as to run at four times enginespeed, but it is to be understood that the invention is not limited to these gear ratios and that other-gearing connections could be utilized if desirable.

In some types of engines especially high speed automobile engines it might be found desirable to automatically disconnect the magneto from the engine, in order toconserve power and to prevent the magneto from running at an excessive speed after the engine had become self-operative, and the ignition current was being supplied by the generator. In Fig. 3, there is shown a centrifugal device which at a predetermined engine speed will disconnect the magneto from the generator. The gear 50 which drives the magneto pinion 51 is loosely journalled upon a generator shaft 90 and is provided with a, clutch member 91 Which is adapted to cooperate with a companion,

to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

I claim: a

1. In an ignition system, the combination with an engine; of a dynamo-electric-machine for providing starting ignition current; another dynamo for supplying running ignition current; connections'between the second dynamo and the engine; relatively high speed gearing between the second dynamo and the first dynamo; and speed responsive means to disconnect said high speed gearing.

2. In an ignition system, the combination with an engine; of a magneto connected therewith for supplying starting ignition; a dynamo connected with the engine for supplying running ignition current; and electro-responsive means to render said magneto inoperative to furnish ignition upon the attainment of a predetermined dynamo voltage.

3. Inan ignition system, the combination with an engine; of a low tension magneto connected therewith; an induction coil normally connected with said magneto; a dynamo connected with said engine and cooperating with said coil; and means for disconnecting said magneto from said engine.

4. In an ignition system, the combination with an engine; of a low tension magneto connected therewith; an induction coil normally connected with said magneto; a dynamo connected'with said engine and cooperating with said coil; and electro-responsive means for disconnecting said magneto from said coil upon the attainment of a predetermined dynamo voltage.

5. In an ignition system, the combination with an engine; of a low tension magneto connected therewith; an induction coil normally connected with said magneto; a dynamo connected with said engine and co operating with said coil; and speed responsive means for disconnecting said magneto from said engine.

6. In an ignition system, the combination with an engine; of a low tension magneto connected therewith; an induction coil normally connected with said magneto; a dynamo connected with said engine and oooperating with said coil; electro-responsive means for disconnecting said magneto "from said coil upon the attainment of a predetermined dynamo voltage; and speed-responsive means for disconnecting said magnet-o from said engine.

7. In an ignition system, the combination with a current source for starting ignition; of an engine driven generator for running ignition; means cooperating with the first source for providing starting ignition, and with the generator to provide running ignition; and means controlled by the generator for rendering the said first source inoperative.

8. In an ignition system, the combination with a current source for starting ignition; of an engine driven generator for running ignition; means cooperating with the first source for providing starting ignition, and with the generator to provide running igni tion; and means controlled by the voltage of the generator for rendering the said first source inoperative.

9. In an ignition system, the combination with an engine; of a plurality of current sources; an ignition coil, means cooperating with said coil and one of said sources to transmit a series of electrical impulses to said coil for ignition purposes; means cooperating with said coil and another of said sources to provide ignition and to render certain of said electrical impulses inoperative.

10. In an ignition system, the combination with a multi-cylinder engine; of a plurality of current sources; an ignition coil; means cooperating with one source and with said coil to provide a series of ignition impulses; means cooperating with another source and with said coil to provide av series of ignition impulses; means for distributing said second series of impulses to the engine and for preventing the passage oi certain of the first series of impulses to the engine.

11. In an ignition system, the combination with a multi-cylinder engine; of a plurality of current sources; an ignition coil; means cooperating with one source and with said coil to provide a series of ignition impulses; means cooperating with another source and with said coil to provide a series of ignition impulses and for rendering ineifectiveicertain of the first series of impulses; and means for distributing said second series of impulses to the engine, while preventing the passage of certain of the first series of impulses to the engine.

12. In an ignition system, the combination with an engine; of a magneto driven thereby; a current source; an ignition coil; a magneto timer for effecting an intermittent flow of a series of impulses to said coil; a second timer for effecting the periodic flow of current from the second current source to the coil and for rendering ineffective certain or" the magneto impulses.

13. In an ignition system, the combination with an engine; of a magneto driven thereby; a current source; an ignition coil; a magneto timer for effecting an intermittent flow of a series of impulses to said coil; a second timer for effecting the periodic flow of current from the second current source to the coil and for rendering ineffective cer tain of the magneto impulses, said second timer being timed in advance of the magneto timer.

14. In an ignition system, the combination with an engine and a plurality of engine driven dynamo-electric-machines; of means cooperating with one machine for providing starting ignition and with another machine for providing running ignition; and means for automatically disconnecting the first mentioned machine from the engine at a predetermined engine speed.

15. In an ignition system, the combination with an engine; of a low tension magneto having an armature; an induction coil cooperating with said magneto; a dynamo connected with said engine and cooperating with said coil; and means responsive to dynamo voltage to; disconnect the magneto from said coil and to provide another path for discharge of the armature current.

16. In an ignition system, the combination with an engine; of a low tension magneto having an armature; an induction coil coopcrating with said magneto; a dynamo connected with said engine and cooperating with said coil; and means responsive to dynamo voltage to provide another path for discharge of the armature current.

In testimony whereof I ailix my signature.

JOHN H. HUNT. iVitnesses:

HAZEL Sonnnmznnenn, MILDRED PEARE. 

